An automatic door system is composed of plural automatic door constituting units. Such automatic door constituting units include, for example, a door control unit, sensors, and an electric lock. The door control unit controls the opening and closing of a door. The sensors include one for sensing a person approaching the door in order to open the door. The sensors include also one for sensing a person near the door in order to prevent the door from colliding with the person when it is opened. The electric lock is for locking the automatic door system when a store with the system installed therein is to be closed. The sensors and the electric lock of the automatic door system are frequently connected to such door control unit. An example of such automatic door system is disclosed in Patent Literature 1.
In the automatic door system of Patent Literature 1, a plurality of sensors and other units are connected to a door control unit composed of a CPU, a RAM, a ROM and an EEPROM via input/output circuits. Many of the sensors are arranged to actuate a switch connected to the door control unit through an input/output circuit when detecting a person.
[Patent Literature 1] JP 10-46918 A